The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
It is known within the field of motor vehicle technology for holding clamps made of plastics materials, for example, to be used for holding on a motor vehicle undercarriage of the motor vehicle, for example on a vehicle frame of the motor vehicle, during the movement of lines such as fuel or brake lines, for example. In this case, the holding clamps have, on the one hand, fastening elements for holding the lines and, on the other hand, further fastening elements for attaching to the motor vehicle undercarriage. For example, in order to attach a holding clamp of this kind to the motor vehicle undercarriage, fastening bolts are provided on said undercarriage at predetermined fastening points. The fastening bolts may be connected to the motor vehicle undercarriage in a substance-bonded manner, for example welded on, integrally formed thereon or connected by adhesion. Alternatively, the fastening bolts may be fixedly connected to the motor vehicle body in a form-fitting or force-fitting manner, for example by screwing-in.
Numerous embodiments of holding clamps are known from the prior art.
By way of example, reference is made here to U.S. Pat. No. 6,036,145 A which describes an integrated system for protecting and fastening pipelines to a carrying structure, in particular to a vehicle body, by means of threaded pins which are welded onto the vehicle body. In this case, the system comprises at least one supporting element which is configured as a one-piece body or clip which, in turn, comprises a central portion with a through-hole housing. When in use, the system has a sleeve which fastens onto a threaded pin; moreover, at least one seat for a pipe and a flat circular supporting region surrounding the through-hole on the side eventually facing the vehicle body. The system contains a protection element integrated with the clip and defined by a channel which protects the pipes and is connected laterally to the clip by a thin flexible strip which allows a rotation of 180° onto the clip, so that the channel can be applied to the clip. The clip and the channel are co-molded simultaneously from the same material, such as from a co-polymer propylene resin with an appropriate filler. During assembly, the clip supporting the pipe is initially fastened to the vehicle body and retained temporarily to the threaded pin by radial tabs inside the through-hole. Once the channel is fitted onto the clip, the sleeve is inserted inside the through-hole and forced axially onto the threaded pin to fasten the channel and the clip lying thereunder by means of a flared head on the sleeve.
Furthermore, EP 1 607 666 A2 proposes a mounting clip for fastening lines such as brake lines, fuel lines, or the like, to the floor of a motor vehicle, in particular of an automobile. The mounting clip has recesses for receiving lines and has a through-opening for screwing the mounting clip with a fastening means on the undercarriage of the motor vehicle. In this case, a nut is, in addition, held rotatably in the mounting clip in a non-detachable manner. In addition, at least one fastening bolt which has a threaded portion is fastened on the motor vehicle undercarriage in such a manner that the mounting clip with the through-opening thereof can be fitted onto the fastening bolt and can be screwed fully automatically against the undercarriage with the nut held rotatably in the mounting clip in a non-detachable manner. In this case, the fastening bolt can be welded to the motor vehicle undercarriage, integrally molded thereon, screwed into the undercarriage or adhered thereto.
A correct attachment of the holding clips to the motor vehicle undercarriage is crucially important for guaranteeing the holding force anticipated for the laid lines, e.g. fuel and/or brake lines, during the running of the motor vehicle and therefore for the operational safety and compliance thereof with existing NVH (noise vibration harshness) requirements.
Various solutions have been proposed in the prior art for providing a simple and reliable means of confirming a correctly realized attachment of holding clamps to the motor vehicle undercarriage.
Hence, for example, EP 0 666 428 A1 describes a bolt-fastening element for use when mounting pipes, in particular fuel or brake lines of a vehicle, with which a fixed engagement of a bolt with the bolt-fastening element is provided, in that a bolt engagement portion of the bolt-fastening element is completely pressed onto the bolt. The bolt engagement portion is fitted with a bolt-receiving hole for receiving the bolt, so that the end of the bolt extends out of the hole. An elongate, elastic part of the bolt-fastening element extends in such a manner that the bolt-receiving hole is closed at a bolt outlet portion of the bolt-receiving hole. The elastic part is pressed out by the bolt end which projects from the outlet of the hole, so that the elastic part is raised from the closed position of the bolt-receiving hole. By looking at the elevated position of the elastic part, it is possible to check that the position of the bolt in the bolt-receiving hole is correct.
In addition, JPH 08 303647 A describes a pipe-holding element which is configured in such a manner that a pipe-retaining element is arranged opposite a pipe-insertion opening and a pipe-receiving seat on a base body on an insertion opening underside. In the insertion opening, a retaining claw is arranged on one or both sides, which retaining claw can be brought into engagement with a bolt of a vehicle. A movable element is arranged on a lower part of the insertion opening and extends from a lower partial wall to a lower center. It is possible to infer from a position of the moving element that the pipe-holding element has been correctly mounted on the pipe-holding element.
A similar solution is described in JPH 07 174127 A with a retaining part base body which is provided to be fastened to a bottom area of a vehicle, in that a clamping element and a bolt-receiving element are configured on the retaining part base body and, in addition, an engagement claw is formed which can be brought into engagement with a bolt of the vehicle. In addition, a movable cover is provided in the bolt-receiving element. This movable cover is initially located in a downward facing position. The movable cover is pressed upwards and elastically deformed into an upwardly oriented position when the bolt is correctly inserted therein in an anticipated manner. Consequently, it is possible for a technician to confirm that the bolt has been inserted to a normal insertion depth according to a change in state of the movable cover.
Another visual means for confirming that a holding clamp attachment has been correctly made is described in JP 2006 046508 A. A holding clamp is provided for fastening to a bolt, in a vehicle for example, which bolt is provided with a thread or a circular outer groove on an outer surface. The holding clamp comprises a bolt locking portion in which a bolt-receiving hole for introducing the bolt is formed and an inspection opening which is configured in the lateral face of the bolt-locking portion for the visual inspection of the bolt introduced into the bolt-receiving hole. The inspection opening is arranged in such a manner that it allows the visual inspection of the front end of the bolt in a state completely introduced into the bolt-receiving hole.
Although the holding clamps known in the art offer possible means of confirming correct attachment to a motor vehicle undercarriage, there is still room for improvement in the field of the reliable holding of lines, such as fuel or brake lines, but also electrical lines, by means of holding clamps on a motor vehicle undercarriage or a motor vehicle body.